Optimization approaches for renewable microgrid applications with hydrogen and battery energy storage – A comprehensive review

Microgrids (MGs) play a pivotal role in enhancing the reliability and resilience of power systems, mainly by incorporating renewable energy sources (RES). However, the variability and uncertainty of RES present significant operational challenges, necessitating the deployment of energy storage systems (ESSs) to ensure grid stability and energy balance. While battery energy storage systems (BESS) have traditionally been used to mitigate the variability of RES, their inherent limitations, including limited cycle life and scalability issues, have prompted growing interest in hydrogen energy storage systems (HESS) as a technically viable, scalable complementary or alternative energy storage solution. Hydrogen-based storage offers several distinct advantages over traditional storage technologies, including long-term energy storage, modular scalability, and potential for multi-sector integration. Given these advantages, this paper thoroughly reviews battery and hydrogen energy storage technologies for renewable energy-based MGs, focusing on their main characteristics, operational behaviors, and strategies for integrating hydrogen–battery hybrid systems. Effective integration of hydrogen–battery hybrid storage systems in renewable energy-based MGs requires advanced optimization techniques. These techniques are essential for managing RES uncertainty, improving economic dispatch, enhancing power quality, and ensuring real-time supply–demand balance. This review paper assesses current optimization approaches used in MG applications, with a focus on performance objectives such as system reliability, economic impact, forecasting, and power quality. This paper explores key research trends and identifies methodological gaps, underscoring the potential of hybrid storage to enhance microgrid sustainability and resilience. The paper concludes with strategic insights and research recommendations to support the continued development and deployment of hydrogen-based storage solutions.